Cinnabar
Cinnabar (Mercury(II) sulfide) · Mineral Specimen / Ore Mineral
Crystal System
Trigonal; commonly occurs in massive, granular, or earthy forms, or as rhombohedral to tabular crystals.
Mineral Group
Sulfides
Chemical Formula
HgS
Formation Process
Hydrothermal; typically forms in low-temperature veins near volcanic activity or hot springs.
About This Crystal
A scarlet-red to brownish-red mineral with a sub-metallic to adamantine luster. It often appears as grain-like coatings on a matrix or in massive earthy aggregates.
Physical Characteristics
Color: Cochineal-red to brownish-red; Streak: Scarlet; Cleavage: Perfect rhombohedral; Fracture: Subconchoidal to uneven; Specific Gravity: 8.1; Non-fluorescent.
Optical Properties
Refractive Index: 2.905–3.256; Extremely high birefringence; Uniaxial positive; High dispersion.
Hardness & Durability
Origin Region
Notable sources include Almadén, Spain; Huancavelica, Peru; Guizhou Province, China; and California, USA.
Hardness & Durability
Mohs hardness: 2.0–2.5; Very soft and brittle; Low durability for jewelry; Highly toxic if inhaled or ingested.
Care & Maintenance
Handle with gloves; store in a sealed container away from children/pets. Wash hands after handling. Avoid acids and high heat.
Rarity & Value
Relatively common as an ore, but bright crystalline specimens are sought after; value depends on color saturation and crystal size.
Special Characteristics
Known for its high density and as the primary ore of mercury; exhibits a distinct scarlet streak.
Lore & History
Used since antiquity as a pigment (vermilion) and in alchemy. Associated with transformation and wealth in traditional lore.